BEIJING, Dec. 12 -- China's South-to-North Water Diversion Project has transferred over 67 billion cubic meters of water to the country's arid northern areas over the past nine years, official data showed.

More than 176 million people have directly benefited from this mega water diversion project, which is the largest in the world, said the Ministry of Water Resources on Tuesday on the ninth anniversary of the project's operation.

Metropolises like Beijing and Tianjin, have relied on the project as a major water source, said the ministry. The project has replenished 10 billion cubic meters of water for ecological purposes over the past years and revived many rivers and lakes.

The country's South-to-North Water Diversion Project has three routes. The middle route, the most prominent one, starts at the Danjiangkou Reservoir in central China's Hubei Province and runs across Henan and Hebei before reaching Beijing and Tianjin.

The eastern route has transferred water from east China's Jiangsu Province to areas including Tianjin and Shandong. The western route is still in the planning stage.